If you are stuck using a 16GB iPhone — or even if you have a 64GB iPhone with tons of apps, videos, movies, and photos — you may find yourself running out of storage space just as you’re trying to install one more must-have, can’t-live-without app or download a movie to watch.

By now you’ve probably tried all the usual tricks to free up space on your iPhone or iPad and have managed to squeeze a little extra storage space from your meager 16GB allotment.

It turns out there is one more bizarre trick you can try. It involves attempting to rent a movie from iTunes and can free up hundreds of megabytes or even gigabytes worth of space on your iPhone or iPad.

Try to download a (really) big movie from iTunes, free up space on your iPhone

Note: This should work on any iDevice and your device does not need to be jailbroken.

Step 1: Before you start, make a note of how much (or little) free storage space you have: go to Settings > General > Storage & iCloud Usage and note the available storage.

Step 2: Next, launch the iTunes Store app > navigate to movies > pick a large movie (make sure it’s bigger than the free storage available on your device). As seen in the demo video below, The Lord of the Rings: The Two Towers may be a good fit as it’s 6.83GB. If that’s not big enough, try War and Peace (1956) — it’s 8.86GB in Full HD (suggested by Redditor toxicoblivion in the thread). Now, tap the Rent button twice.

Note: You won’t be charged for renting the movie since you don’t have enough storage available and it won’t download to your device.

Step 3: When you see a popup message telling you that there’s not enough available space on your device to download the movie, tap Settings > General > Storage & iCloud Usage. When you look at your available storage space now, you should see a significant increase in that number.

Step 4: Now go back to the iTunes Store app and repeat the entire process. Every time you check back you should see another chunk of storage space added to your available number. Users who have tried this trick have reported between a few hundred megabytes and a few gigabytes of extra space freed up on their devices.

Note: Either stop when the available storage number stops increasing or as soon as you have enough space to actually download the movie — at which point you’ll be charged for the rental.

How and why does this work?

It’s unclear how this unconventional trick works but Redditor eavesdroppingyou — who originally shared this tip — suggested that iOS “erases some useless data from different apps to try to download the movie.”

See this bizarre trick in action below:

Image credit: wackystuff, Flickr